Abstract: To make available to the vehicle control systems more information on the forces and directions of the forces which act on the individual tires, in order to determine these forces, the displacements between the outer ring and inner ring in the wheel bearings are measured in a contactless fashion using ultrasound. Displacements are measured by one or more sets of an ultrasound transmitter and a receiver on the stationary ring and a reflection surface on the rotating ring for reflecting back the ultrasound energy. The measured time until the signal is received enables displacement to be determined. It is possible to use these displacements to calculate the forces acting from a knowledge of the spring characteristic of the wheel bearings.

Abstract: A micromechanical sensor unit for detecting acceleration has pendulums each with a spiral spring and a seismic mass. Supports each being connected to a respective one of the pendulums, and position sensors, each two of the position sensors is associated with a respective one of the pendulums. Each position sensor and an associated pendulum form a switch with a defined triggering threshold and at least two switches respond to the same direction of acceleration. At least one switch is a safing sensor with a separate tap of a sensor signal.